Field of the Invention
This invention relates generally to attachable couplings of the male-stem, ferrule type for use with reinforced, flexible hose but more particularly, this invention relates to such couplings, which employ a ferrule with or without an insert for gripping a hose end, wherein the ferrule may include a torque communication portion.
Description of the Prior Art
Couplings of the type that are post assembled to an end of a finished hose product typically have a male-stem portion that is insertable into a hose end and a ferrule that is concentric with the male-stem. Together, the male-stem and ferrule define an annular cavity for receiving a hose end. A coupling is retained by pinching the hose end in the annular cavity between the ferrule and stem such as by either radially reducing some part or element of the ferrule or by radially increasing the size of the male-stem.
Some couplings are of the reusable type and use a mechanical means of the coupling such as threaded members that activate means for pinching a hose against a stem. An example of such a reusable coupling appears in European patent EP0241651 where a plurality of coaxial rings having alternating frustoconical surfaces are axially pressed together by a threaded member to wedge alternate rings radially inwardly. The wedged rings pinch a hose against a stem. Such reusable couplings are usually expensive because the co-acting parts forming the coupling are typically machined from barstock. Furthermore, the amount of pinching cannot be precisely controlled for a range of hoses when the coupling is attached to a hose.
Crushable types of ferrules that may be of different sizes for different hose constructions having the same bore size are preferred for accurately controlling how an end of a hose is pinched. For example, radially reducing the size of a ferrule by crushing it to a smaller diameter may be accomplished through crimping processes that use a plurality of circumjacently arranged die fingers.
Oftentimes, a serrated stem with a ferrule locking collar is used for high pressure hoses that are subjected to pressure impulses. For convenience of assembly, a ferrule may be pre-attached to a stem such as by crimping an end portion of the ferrule to the ferrule locking collar. While preattachment of a ferrule to a stem has advantages associated with reducing the number of parts for assembly to a hose, it introduces a disadvantage as to the number of parts required for a line of hose sizes because some hoses require the same size stem but different size ferrules. For example, three different size ferrules may be used with the same size stem for coupling one-half inch ID hose having different tube, reinforcement, and cover combinations. Consequently, some manufacturers prefer to select an appropriate ferrule for a hose when it is to be crimped on a hose so as to minimize inventory.
To address these and other problems, a ferrule for use in attaching a hose end portion to a male-stem was developed and patented in U.S. Pat. No. 5,267,758, wherein the ferrule has a crushable socket portion which retains a bendable sleeve-like insert having substantially a “C” shape. This insert employs means, such as ribs formed along an inside surface, for gripping a hose end. In another form, the sleeve-like insert has a plurality of offset teeth at circumjacently spaced end portions of its “C” shape which teeth interdigitate with each other when the ferrule is used for attaching a hose end portion to a male-stem. The teeth accommodate a range of hose diameters and hose constructions. However, notably the disclosed and claimed crimped-on coupling is made-up of three primary components: a stem, adapted to be inserted into a hose; a staked collar, which includes wrenching flats or the like, typically employed as a “back-up hex”; and a ferrule, which houses the aforementioned “C” shaped insert.